The passage of a planar-wavefront optical beam through a turbulent, index-of-refraction-variant flowfield imprints dynamically changing aberrations on the wavefront; these aberrations have detrimental effects on the performance of optical systems making use of the beam.
Because the specular peak is narrow in the perfect crystal, the crystal plane is close to being flat over a large area, and therefore all the contributions can form a nearly planar wavefront and can simultaneously meet the Bragg condition.
As described in the previous section, the linear interpolation of the phase angle is based on the propagation model of a single planar wavefront.
These give rise to individual focal sources of excitation on the epicardium, leading to a less planar wavefront.
In the majority of recordings, both in LV and RV of WT and Scn5a+/− hearts, there was a single planar wavefront arriving at the epicardium with the intraepicardial vector travelling from the apex to the base of the heart (Fig. 3, A and B).
The description in Fig. 3 ▸ refers to a perfect crystal when all the scattering points are in the same plane and the maxima of the spherical waves all coincide and form a planar specular wavefront S (Fig. 4 ▸ a).
A stimulus of magnitude 4.0 × 10 μA/cm and duration of 2.0 ms was applied to surface nodes within the apical region of the mesh (z < 5.0 cm) which elicited the propagation of a quasi-planar wavefront in approximately an apicobasal direction.
This focal activation spread out from the septum and caused the wavefront on the epicardium to be significantly less planar (increased curvature) throughout the remainder of the activation sequence, relative to the more uniform and planar wavefront in the simplified model, particularly evident in the epicardial 58- to 72-ms images.
Without the gold cover, the subwavelength-scale bare Si NW distorted the regular interference pattern (left, Fig. 2d), whereas the presence of the gold cover restored the planar wavefronts and made the NW invisible (right, Fig. 2d).
